This ongoing project is directed at elucidating and then minimizing the hemolysis which occurs in blood flowing in contact with solid surfaces. In this second year, the two major thrusts will deal with blood chemistry and hydrodynamics. In the former, various chemicals will be used as blood additives to influence erythrocyte membrane properties, deformability, and mechanical fragility in general. The effects of these additives will be interpreted in terms of cell structure and should shed light on the mechanisms of shear-induced hemolysis. The second thrust is directed at flow studies in a variety of capillary-type geometries, to assess the importance of complex geometries and corresponding velocity fields for inducing hemolysis. Various inlet geometries, severe and gradual tapers in diverging and converging flow, and branched flows will be investigated and results compared with predictions of analytical models.